We have a project that only has one channel and uses the Octopus default life cycle. They last deployed this project on 7/18 to production. However, since then for some reason they cannot deploy to production anymore.
I’ve confirmed there are no phases associated with the default life cycle. I did notice it does say " This lifecycle will use the default conventions. They allow deployment to any environment, so long as environments are deployed in the order that they are defined on the [environments] page. Use the Add phase button to explicitly define your own phases or to restrict the lifecycle to specific environments."
There is one environment that this project does not deploy to (UAT); that environment does appear between QA and Production in the environment list, but this has never been an issue before. (This can be seen in the screenshot that the previous releases have skipped UAT.) We did update Octopus last month, but I don’t recall the exact date.